Discovering thousands of planets beyond our solar system counts as a “eureka” moment in human exploration. But the biggest payoff is yet to come: capturing evidence of a distant world hospitable to life.
In just over 20 years of exploration, ground and space-based observations have turned up more than 3,200 confirmed exoplanets in the few slices of our galaxy we've been able to search. Add unconfirmed planetary candidates and the number jumps to more than 5,600.
Many of the planets found so far are gas or ice giants, with little chance of a solid surface harboring a warm little pond. But we've also found some rocky worlds in Earth's size range.
Even with the expected advances in observing technology in years to come, we're unlikely to know the precise nature of any life we might detect, be they crusts of algae or loping, six-legged giraffes.
Still, among those rocky, Earth-like worlds, we could catch tantalizing glimpses of the right conditions for life.

Even if NASA hasn't discovered aliens, or life beyond Earth, perhaps it has discovered an exoplanet or exoplanets hospitable to life.